Apparatus for separating and recovering fumes of arsenic, &amp;c.



Patented Oct. I4, |902.

G. C. STONE. APPARATUS FOR SEPARATING AND RECUNERING FUMES 0F ARSENIC,c.

(Application led Oct. 29, 1901.)

(No Model.)

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UNITED STATES PATENT OFFICE.'k

GEORGE C. STONE, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO THE NElV JERSEYZINC COMPANY, A CORPORATION OF NEW JERSEY.

APPARATUS FOR SEPARATING AND RECOVERING FUMESVOF ARSENIC, &c.

SBECIFCATION forming part of Letters Patent No. 711,188, dated October14, 1902.

i Application filed October 29| 1901. Serial No. 80,452. (No model.)

T0 a/ZZ whom it may concern):

Beit known that I, GEORGE C. STONE,a citizen of the United States,residing at Jersey City, county of Hudson, and State of New Jersey, haveinvented certain new and useful Improvements in Apparatus for Separatingand Recovering Fumes of Arsenic and the Like; and I do hereby7 declarethe following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

My invention relates to apparatus for separating and recovering fumes ofarsenic and the like from furnace-gases in the manufacture of sulfuricacid or sulfuric anhydrid.

In the utilization of f urnace-gases, particularly the gases evolvedfrom ore-roasting furl naces, for the manufacture of sulfuric acid orsulfuric anhydrid the arsenic and other volatile products which wouldconstitute objectionable impurities in the acid product must be removedbefore the synthetic production of the acid or the anhydrid isaccomplished.

My present invention comprises a separator and condenser through whichthe furnacegases, cooled to substantially the point of deposition of thearsenic and the like, are passed and in which the arsenic and likeconstituents are condensed and retained upon or Within a body of filtermaterial interposed in the path of the gases through the apparatus.

In the accompanying drawings, wherein I have illustrated apparatusadapted for the practice of my invention,Figure1 is a verticalcross-section through the condenser and separator, and Fig. 2 is ahorizontal'section` taken at right angles vto Fig. 1.

Referring to the drawings, the condenser and separator comprises acasing, preferably of metal, formed of central externally-Rangedbox-like sections 1, to which are Vsecured end sections 2. Each of saidend sections is proat diagonally opposite points in the casing. Asupply'pipe 11' connects the furnace or other source with chamber A,while an outlet-pipe 12 leads the purified gases to the oxidizingapparatus. The intermediate sections are secured to the end sections andto each other by suitable bolts'passing through the abutting Ranges 13.Each of said intermediate sections is provided with a series of in!ternal flanges 4, which when the sections are joined together form aseries of U-shaped pockets opening alternately toward the longitudinalchannels A B', communicating with the inlet and outlet channels A and B,respectively. Mounted in each of the rectangular frame-like structuresformed by these Ranges is a screen or condenser comprisinga sheet ofsteel-wire gauze or the like 5, supported on the projecting rim 4;' ofthe Ranges 4, upon which sheet is placed a layerof filter material 6,preferably of asbestos or like refractory material 'that is unaffectedby heat or chemical action of the gases. This layer, which constitutesthe condensing and separating medium proper, is secured in place byanother sheet'of wire-gauze 7,7which in turn is held in position by aframe 8, attached to the Ranges 4 by bolts. It will be seen that eachintermediate section of the casing carries two screen or condensersections, with a space between them communicating with the gas-inlet,while the adjacent screens of contiguous sections form .pocket-likerecesses opening into the inlet-channel. The apparatus may be quicklydismantled for the purpose of removing one or all of the screen-sectionsor for the purpose of supplying additional or replacing old or damagedscreens. Likewise separate casing-sections may be added to or removedfrom the apparatus to increase or diminish the capacity of theseparator. y

The operation of the apparatus as described is as follows: The gasesfrom thefurnace are Ycooled to substantially the temperature ofdeposition of the fumes of arsenic and like volatile constituents.Thiscooling may be accomplished in any well-known manner. The mixedgases enter at 11, pass by Way of chambers A and A into the spacesbetween the screens 6, thence laterally through said screens, where thearsenic and like volatile IOC constituents are condensed and retainedupon and within the body of the filter mass of the screen. The sulfurfumes, which are not condensed at the temperature employed to separatethe arsenic and other impurities, pass through the separator-screens andby Way of chambers B/ B and exit-pipe l2 to the oxidizing apparatus,Where the acid or the anhydrid is formed. When the separatorscreens havetaken up sufficient quantities of condensed fumes, the apparatus isdisconnected from the gas supply and the acidmaking apparatus for thepurpose of removing the deposits of arsenic and the like from thescreens and simultaneously cleaning and preparing the screens forfurther use. This is accomplished by heating the apparatus to a degreesufcient to volatilize the products deposited in and upon the screen,or, preferably, by removing the screens and subjecting the lter materialto the action of heat either to drive off the deposited matter or toseparate and recover the various desirable elements, particularlythearsenic, by any of the Well-known methods of fractional distillation, orinstead of utilizing heat for the purpose the deposited material may beremoved or recovered from the screens by Washing or treating withsuitable chemical reagents. After the screen material has been cleansedit is again applied to the apparatus and the operation repeated as oftenas necessary.

In the apparatus shown each section contains tWo separator and condenserscreens or sections and single passages for the entrance and exit,respectively, of the gases, in which apparatus the gas-passages are soarranged that the gases pass through all of the screens orcondensersections simultaneously. It

may, if preferred, be arranged with a single screen in each section ofthe casing or with the gas-passages in separate sections. When itisfound desirable, the gas-passages may be so arranged that the gases passthrough two or more condenser-sections in succession before they areallowed to pass into the exitchamber, or the gases may be passedsuccessively through a series of separate condensers of the characterdescribed.

What I claim as my invention is- 1. A condenser and separator forarsenic and the like, contained in furnace-gases,comprising a casingmade up of an inlet end-section and an outlet end section providedrespectively with an inlet and an outlet conduit, and removableintermediate sections having gas-passages communicating with thegas-passages of the end sections, said intermediate sections containingfilter-screens; substantially as described.

2. A condenser and separator for arsenic and the like contained infurnace-gases, comprising a casing made up of an inlet end section andan outlet end section, having each an internal gas-passage and providedrespectively with an inlet and an outlet conduit,and removableintermediate sections provided with gas-passages constituting acontinuation of the gas-passage of the inlet end section, and withoppositely-disposed gas-passages constituting a continuation of thegas-passage of the outlet end section, and interposed filter-screens,substantially as described.

3. A condenser and separator for arsenic and the like contained infurnace-gases,comprising a casing having inlet and outlet end sections,and removable intermediate sections, each provided with a pair oftransverse lter-screens separated from each other by an interveningspace, and being further provided at top With a gas-passagecommunicating with said intervening space, and at bottom with agas-passage communicating with the exit sides of the screens and withthe gas-passage of the outlet end section, sub.- stantially asdescribed.

In testimony whereof I afliX my signature in presence of two witnesses.

GEORGE C. STONE.

Witnesses: i

A. P. COBB, H. G. OLoPPER.

